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Re: The Ordered List Ontology

From: Dan Brickley <danbri@danbri.org>
Date: Wed, 30 Jun 2010 20:15:42 +0200
Message-ID: <AANLkTinzp1zG3lqIYYx8-rsZCzLQlXFM67hyOE6HcFkP@mail.gmail.com>
To: Pat Hayes <phayes@ihmc.us>
Cc: Toby Inkster <tai@g5n.co.uk>, Graham Klyne <GK@ninebynine.net>, Bob Ferris <zazi@elbklang.net>, Linked Data community <public-lod@w3.org>, Semantic Web <semantic-web@w3.org>
On Wed, Jun 30, 2010 at 6:34 PM, Pat Hayes <phayes@ihmc.us> wrote:
>
> On Jun 30, 2010, at 6:45 AM, Toby Inkster wrote:
>
>> On Wed, 30 Jun 2010 10:54:20 +0100
>> Dan Brickley <danbri@danbri.org> wrote:
>>
>>> That said, i'm sure sameAs and differentIndividual (or however it is
>>> called) claims could probably make a mess, if added or removed...
>>
>> You can create some pretty awesome messes even without OWL:
>>
>>        # An rdf:List that loops around...
>>
>>        <#mylist> a rdf:List ;
>>                rdf:first <#Alice> ;
>>                rdf:next <#mylist> .
>>
>>        # A looping, branching mess...
>>
>>        <#anotherlist> a rdf:List ;
>>                rdf:first <#anotherlist> ;
>>                rdf:next <#anotherlist> .
>>
>
> They might be messy, but they are *possible* structures using pointers,
> which is what the RDF vocabulary describes.  Its just about impossible to
> guarantee that messes can't happen when all you are doing is describing
> structures in an open-world setting. But I think the cure is to stop
> thinking that possible-messes are a problem to be solved. So, there is dung
> in the road. Walk round it.

Yes.

So this is a point that probably needs careful presentation to new
users of this technology. Educating people that they shouldn't believe
any random RDF they find in the Web, ... now that is pretty easy.
Still needs doing, but it shadows real world intuitions pretty well.

If in real life you think the Daily Mail is full of nonsense, then it
isn't a huge leap to treat RDFized representations of their claims
with similar skepticism (eg. see
http://data.totl.net/cancer_causes.rdf for a great list of Things The
Daily Mail Say Might Cause Cancer).

*However* it is going to be tough to persuade developers to treat a
basic data structure like List in the same way. Lists are the kinds of
thing we expect to be communicated perfectly or to get some low-level
error. A lot of developers will write RDF-consuming code that won't
anticipate errors. Hopefully supporting software libraries can take
some of the strain here...

cheers,

Dan
Received on Wednesday, 30 June 2010 18:16:22 GMT

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